1. Field of the Invention
The present invention relates to an air dam that attaches to the trailing edge of a ceiling fan blade and acts as a spoiler in order to redirect the turbulent airflow created by the rotating fan blade in a downward direction.
2. Background of the Prior Art
Ceiling fans are used to create downward air flow in order to help cool occupants of a room wherein the ceiling fan is located. Ceiling fans can be used alone or can be used to supplement the cooling air emitted by an air conditioning system. The ceiling fan has one or more ceiling fan blades that rotate under the action of a motor held within the ceiling fan housing. The leading edge of the rotating ceiling fan blade has a downward angle of attack that directs the downward air flow. The more air flow, the more cooling capacity delivered by the ceiling fan.
Some ceiling fan manufacturers design fan blades that deliver the maximum air flow at varying speeds of rotation and fan blade size. Yet these blades tend to be utilitarian in appearance and are not well received by the consuming public. Accordingly, many ceiling fan manufacturers place a premium on aesthetics of the overall ceiling fan design, including the appearance of the fan blades, and worry less about air movement efficiency of the fan blades used by the ceiling fan. As such, a person may install a ceiling fan that harmonizes with the decor of the room into which the fan is installed, only to have a ceiling fan that delivers less than an ideal air flow toward the occupants of the room where the ceiling fan is installed. Such a fan either moves little air at slow speeds or directs much of the air being moved in a lateral as opposed to a downward direction. The user is then forced to increase the fan speed in order to reach a desired comfort level, with the attendant increase in fan noise and electricity use. As such discoveries are typically made after the ceiling fan is purchased and installed, the person must accept a less than ideal situation.
To address such problems, devices have been proposed that increase the air flow of a ceiling fan's blades during rotation. Some such devices are attached to either the leading edge and/or trailing edge of the rotating fan blades in order to alter the geometry of the fan blade so as to increase the volume of air moved for a given rotational speed. Similarly, some prior art devices add wing tips to the distal ends of the ceiling fan blade for a similar purpose. Such prior art devices, which come in a multitude of architectures, may move a greater volume of air, but not without compromise. The increase in air movement corresponds to a greater load on the ceiling fan motor due to the increased drag and additional weight of the altered blade. Some prior art devices, in order to move a greater volume of air, transform the ceiling fan blade into more of an airfoil shape so that substantial Bernoulli-type lift is created which increases the load on the motor, thereby decreasing fan efficiency. Many prior art devices are large, bulky and unattractive.
What is needed is a device that increases a ceiling fan's efficiency while addressing the above mentioned shortcomings found in the art. Such a device should not substantially increase the loading on the motor of the ceiling fan blade by substantially increasing the volume of air moved by the blades. Rather, such a device should have a directional effect so as to direct the air that is being moved by the rotating fan blades in a downwardly direction toward the occupants of the room whereat the ceiling fan is installed. Such a device must not transform the fan blade into an airfoil shape or otherwise impact substantial Bernoulli-type lift, either positive or negative, onto the fan blade.